The invention relates generally to cooking apparatus, especially cookers cooking products conveyed on conveyor belts.
Cookers, such as steam cookers and blanchers, are often used to cook food products, such as shrimp. In continuous shrimp cookers, shrimp are conveyed through a steam-filled chamber on a conveyor belt. To uniformly cook the shrimp, which may sit on the conveyor belt in a thick layer, it is often necessary to reposition the shrimp one or more times along the belt's path through the cooking chamber. The conveyor belt is guided around an upper, forward roller and a lower, rearward roller in an S-shaped back flip along the conveying path. Shrimp drop off the upper portion of the belt winding around the upper roller and land on the lower portion of the conveyor belt exiting the lower roller. In this way, the shrimp are repositioned on the belt with previously unexposed portions exposed to the cooking steam. Such a repositioning flip for a flighted belt is described in U.S. Pat. No. 5,410,951, “Apparatus and Method for Continuous High-Volume Steam Cooking,” May 2, 1995, to Ledet et al. In the Ledet cooker, the upper roller, a sprocket, and the lower roller, which has deep notches to accommodate the belt's flights, rotate at the same speed as the belt because they positively engage structure in the modular belt conveying the food products.
One problem not addressed by the Ledet cooker is the build-up of debris, such as shrimp whiskers, shell fragments, and slimy fluids on the conveying surface of the belt. Cookers similar to the Ledet cooker use idle rollers as the upper and lower rollers to provide a back flip for a flightless conveyor belt. A brake on the lower roller is periodically activated to halt its rotation so that the conveying surface of the belt slides on the braked roller to scrape off debris. But braking the lower roller puts an added load on the belt and its drive motor.